1. Field of the Invention
The present invention relates to a method for recognizing digital information in a digital information transmission, particularly an information transmission in mobile radio communications systems, and to a circuit arrangement for implementing the method.
2. Description of the Prior Art
Speech, data and images are forms of information which are to be transmitted in known, wire-bound communications systems and in future mobile radio communications systems. Given a transmission of information, particularly digitized information, in a mobile radio communications system, a problem arises in that, due to so-called multi-path propagation on the radio path, fading arises which can cause information bit errors during transmission.
Methods are known by which a sampling pulse is derived at the respective receiver from the digital information received, the sampling pulse being employed for placing a sampling time into the respective area of an information element in which the pulse to be sampled and which represents the information element assumes its suspected quasi-stationary state, cf. for example, the German allowed and published application No. 1,804,719. These known methods, however, have the disadvantage that, in those cases in which pulses representing information elements are distorted in amplitude and/or in phase due to disruptive influences, a bit error can be simulated precisely in the respective area sampled, although the appertaining pulse, when viewed as a whole, can be free of error.
In previous mobile radio communications systems, as favorable as possible a bit error rate is sought by applying different encoding methods, for example, "forward error correcting". This philosophy, however, is opposed by the desire to achieve a standardization of the operating modes.